Sinovac’s Covid-19 Vaccine Proven Efficient in Brazil Trials

SÃO PAULO – Sinovac Biotech Ltd.’s Covid-19 vaccine, which scientists hope can help fight the pandemic in developing countries, has exceeded the 50% threshold for effectiveness in late-stage studies in Brazil, which means that regulators can give it the green light to use, said those involved in its development.

Brazil is the first country to complete phase 3 trials of the Chinese company’s CoronaVac vaccine, which is also being tested in Indonesia and Turkey. With Covid-19 largely under control in China, the country’s vaccine developers have had to conduct their clinical trials abroad.

Those involved in the Brazilian trials who completed Phase 3 last week told the Wall Street Journal that the results showed CoronaVac at an effective rate of over 50%, the threshold for a vaccine considered viable by international scientists can be. People refused to provide any further information. However, scientists following the development of the vaccine expect efficacy comparable to other Covid-19 vaccines, which studies have shown to be 95% effective.

“Everyone is hoping for an effectiveness rate of over 90%,” said Domingos Alves, a professor at Ribeirão Preto Medical School in São Paulo who specializes in health data analysis. “The results from the first test phases were very good.”

The Brazilian Butantane Institute, the São Paulo state-backed research center that tested CoronaVac, is expected to announce the vaccine’s effectiveness rate on Wednesday. Butantane said Monday that he considered any information given at the time about the vaccine’s effectiveness as “mere speculation”.

While wealthy nations buy doses of vaccine from Western drug manufacturers, poorer nations place their hopes on China. Sinovac’s CoronaVac vaccine can also be stored in a standard refrigerator at around 36 to 46 degrees Fahrenheit, making it easier to transport and store in less developed regions.

João Doria, Governor of São Paulo, has spearheaded Brazilian development of the Chinese vaccine, which is expected to be one of the first to be approved for use in the hard-hit Latin American country. Brazil has registered more than 187,000 deaths from Covid-19 to date and continues to report tens of thousands of new cases every day – dire facts that make it an ideal testing ground for vaccines.

Rio de Janeiro’s Ipanema Beach on Sunday.


Fabio Motta / Shutterstock

Around 11,000 health workers in the Brazilian capital and seven other states participated in the phase 3 trials, with half receiving CoronaVac and the other half receiving a placebo, the São Paulo government said.

More than 200 of these volunteers became infected with Covid-19 during the studies. Researchers were given a sample large enough to calculate the vaccine’s effectiveness by counting how many of those infected volunteers were taking CoronaVac or the placebo, Butantan’s director Dimas Covas said in an interview.

Mr Covas said the Phase 3 results would be reviewed by an independent committee of five scientists that would confirm an effectiveness rate. While refusing to identify the specialists, Mr Covas said they were from countries other than Brazil or China.

The results of the studies will be presented to drug regulatory authorities in Brazil and China on Wednesday. Mr Covas said it was possible for CoronaVac to be approved in China before Brazil.

In Brazil, the vaccine was at the center of a bitter political battle between Doria and President Jair Bolsonaro, who dismissed the disease as nothing more than a “minor flu”.

President Jair Bolsonaro posed this month with a character created to promote the country’s vaccination efforts.


Andressa Anholete / Getty Images

A fierce critic of China, Mr Bolsonaro has refused to buy CoronaVac for other states and recently suggested on social media that the vaccine could cause disability and even death. Some doctors fear Mr Bolsonaro could put pressure on the country’s regulator, Anvisa, to delay its approval.

Mr Doria said he had planned to start a television campaign to get Brazilians to vaccinate and would do whatever it takes to get Anvisa to approve CoronaVac in time for the vaccine to be administered in São Paulo on January 25th .

“If necessary, we will go to the Supreme Court to save lives,” Doria said in an interview.

Mr Doria said he plans to vaccinate the entire state, which is home to about a fifth of Brazil’s population, by the end of July – almost a year earlier than the federal government promised to vaccinate the rest of the country’s population.

If people refuse to take the vaccine, they will be banned from shopping malls, cinemas, theaters and refused access to planes and buses, Doria said. “You will feel left out.”

As a former television star and businessman, Doria said he had private sector support in the state to push the measure through.

Butantane, which began manufacturing Sinovac’s vaccine in Brazil this month, has agreed with the private Chinese company to become the distributor for CoronaVac in Latin America. In May, Butantane plans to ship the vaccine to Argentina, Bolivia, Colombia, Honduras, Peru and Uruguay, Covas told the Journal.

Butantane, which funded the Phase 3 trials, will use any profits from the distribution of the vaccine to reinvest in the factory, which produces up to a million doses of CoronaVac daily, Covas said.

Latin American countries have struggled to secure enough Covid-19 vaccines for the region, which has so far recorded more than 450,000 deaths from the disease.

While wealthier countries are buying up supplies of Covid-19 vaccines from western drug makers that are still in development, China and Russia are offering their quick shots to poorer countries. Here’s what they hope to get back to. Illustration: Ksenia Shaikhutdinova

Colombia is initiating limited vaccine testing this week, President Ivan Duque said. Mass vaccinations will begin in February, when the country is due to receive its first major vaccine shipment, nearly two million doses from Pfizer Inc.

In Argentina, President Alberto Fernandez’s government has reached an agreement with Russia to receive 10 million doses of the Sputnik V vaccine. Last month Argentina also signed a contract with AstraZeneca PLC to receive 22 million doses of its vaccine. These vaccines are expected to be received in the first half of next year.

Meanwhile, the Peruvian government has been criticized for not receiving Covid-19 vaccines as authorities do not know exactly when the first shots will hit the hardest hit country

More about the Covid-19 vaccines


Write to Samantha Pearson at [email protected] and Luciana Magalhaes at [email protected]

Copyright © 2020 Dow Jones & Company, Inc. All rights reserved. 87990cbe856818d5eddac44c7b1cdeb8

Comments are closed.